A solution known from WO 01/45138 is based on the use of a ceramic material of the composition Pb0.97Nd0.02(Zr0.5515Ti0.4485)O3 in piezostacks with Cu internal electrodes, the production thereof is carried out by binder removal and sintering in air.
The properties of the known actuators with the ceramic composition Pb0.97Nd0.02(Zr0.5515Ti0.4485)O3 with in each case 360 internal electrodes and a ceramic layer thickness of 80 μm in sintering together with Cu internal electrodes are summarized in the following table, such as they are measured after a polarization with E=2 kV/mm (a) at room temperature and (b) at 180° C. Apart from the small-signal properties of the dielectric constants (DC) and the temperature dependence of the DC, the large-signal dielectric constant is also indicated here, which can be calculated from the polarization by means of a voltage, which for example leads in the case of the actuators to a deflection of 40 μm.
Small-Large-signal DCsignal DCTK ppm/KD33 pm/VWg %E mJa1214 ± 303110 ± 873936 ± 82592 ± 1850.4 ± 0.450 ± 2b2772 ± 50632 ± 1156.5 ± 0.434 ± 1
By means of the polarization at higher temperature, the efficiency is improved from 50% to 56% and the energy loss is reduced from 50 mJ to 34 mJ.